Android: How to send message programmatically by using WhatsApp, WeChat?

I got the Solution.. Here I am posting the answer so that it may help other people who may have same doubt..

For Share through any application…

public void sendAppMsg(View view) {

    Intent intent = new Intent(Intent.ACTION_SEND);
    intent.setType("text/plain");
    String text = " message you want to share..";
    // change with required  application package  

    intent.setPackage("PACKAGE NAME OF THE APPLICATION");
    if (intent != null) {
        intent.putExtra(Intent.EXTRA_TEXT, text);//
        startActivity(Intent.createChooser(intent, text));
    } else {

        Toast.makeText(this, "App not found", Toast.LENGTH_SHORT)
                .show();
    }
}

Note : change *PACKAGE NAME OF THE APPLICATION as per your requirement like

Example : USE

//Whatsapp
    intent.setPackage("com.whatsapp");`

//Linkedin
    intent.setPackage("com.linkedin.android");

//Twitter    
    intent.setPackage("com.twitter.android");

//Facebook
    intent.setPackage("com.facebook.katana");

//GooglePlus
    intent.setPackage("com.google.android.apps.plus");

This should help to send message using whatsapp:

public void sendWhatsAppMsg() {

    Intent waIntent = new Intent(Intent.ACTION_SEND);
    waIntent.setType("text/plain");
            String text = "testing message";
    waIntent.setPackage("com.whatsapp");
    if (waIntent != null) {
        waIntent.putExtra(Intent.EXTRA_TEXT, text);//
        startActivity(Intent.createChooser(waIntent, text));
    } else {
        Toast.makeText(this, "WhatsApp not found", Toast.LENGTH_SHORT)
                .show();
    }

}

To send direct message to any whatsapp user use following code :

private void sendMessageToWhatsAppContact(String number) {
    PackageManager packageManager = context.getPackageManager();
    Intent i = new Intent(Intent.ACTION_VIEW);
    try {
        String url = "https://api.whatsapp.com/send?phone=" + number + "&text=" + URLEncoder.encode(CommonStrings.SHARING_APP_MSG, "UTF-8");
        i.setPackage("com.whatsapp");
        i.setData(Uri.parse(url));
        if (i.resolveActivity(packageManager) != null) {
            context.startActivity(i);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}